Conventionally, one-part urethane resin compositions that utilize moisture curability have been widely used as adhesive agents or the like.
For example, Japanese Unexamined Patent Publication No. 2013-095759 describes “a polyurethane adhesive composition for resin glass, the polyurethane adhesive composition containing:
a preliminary composition containing a urethane prepolymer obtained by reaction of a mixture of a polyether triol having a number average molecular weight of 1000 to 7000 and a polyether diol with 4,4′-diphenylmethane diisocyanate under a condition that the equivalent weight ratio of the isocyanate group to the hydroxy group is from 1.1 to 2.5;
an adhesion promoter A obtained via addition of 3-(N-phenyl)aminopropyltrimethoxysilane and the biuret of hexamethylene diisocyanate under a condition that the equivalent weight ratio of the isocyanate group to the amino group is from 1.5/1.0 to 9.0/1.0; and
an organotin compound;
a content of the adhesion promoter A being from 2 parts by mass to 10 parts by mass per 100 parts by mass of the urethane prepolymer; and
a content of the organotin compound being from 0.001 parts by mass to 0.5 parts by mass per 100 parts by mass of the urethane prepolymer”. Furthermore, Japanese Unexamined Patent Publication No. 2013-095759 describes dioctyltin dilaurate, dibutyltin laurate, and the like as the organotin compound.
When the inventor of the present technology produced a composition containing a compound in which an alkyl group bonded to a tin atom has two or more carbons, such as dioctyltin dilaurate and dibutyltin laurate, using Japanese Unexamined Patent Publication No. 2013-095759 as a reference and evaluated the composition by applying the composition onto a coated plate with poor adhesion containing no primer, it was found that such a composition may exhibit low adhesion to the coated plate with poor adhesion.